And one with trembling hands clasps his cold head, And fans him with her moonlight wings, and cries, "Our love, our hope, our sorrow, is not dead; See, on the silken fringe of his faint eyes, Like dew upon a sleeping flower, there lies A tear some Dream has loosen'd from his brain." Lost Angel of a ruin'd Paradise! She knew not 'twas her own; as with no stain She faded, like a cloud which had outwept its rain.
Death is back, holding Adonais-Keats in "her" arms. Normally, when Death is made into a character, it comes to take someone away. But this time, Death is just as sad as everyone else that the youth is dead, calling him "Or love, our hope, our sorrow" and commenting on his beauty (his "silken fringe" is his eyelashes).
She is so sad, in fact, that she insists he's still alive. Death even says she sees a tear in his eyes, caused by the brain that still has a few dreams left.
The speaker calls Death the "Lost Angel of a ruin'd Paradise," which indicates that she hails from some type of heaven, one that has been ruined by something. Because Keats doesn't appear to be dead, she knows she cannot take him, so she leaves ("faded, like a cloud").
Or does she leave because he's too perfect to be taken into the afterlife?